Integrated Process and System for Steam Cracking and Catalytic Hydrovisbreaking with Catalyst Recycle

Abstract

This invention relates to a process for cracking hydrocarbon feedstock containing resid comprising: (a) heating a hydrocarbon feedstock containing resid; (b) adding molecular hydrogen to said heated feedstock to form a mixture stream; (c) adding a catalyst containing metal-sulfide particles to said heated feedstock and/or said mixture stream; (d) reacting said mixture in a catalytic hydrovisbreaking reactor under conditions of temperature, pressure and residence time sufficient to catalytically hydrovisbreak at least a portion of said resid into hydrovisbroken hydrocarbon components; (e) passing said reacted mixture stream into a high pressure separator and separating hydrogen from said reacted mixture; (f) passing said reacted mixture through a knockout drum to remove catalyst and unreacted or uncracked resid as a bottoms stream; and (g) passing said catalytically hydrovisbroken hydrocarbon components into a steam cracking furnace and thermally cracking said hydrocarbon components to form light olefins, alternately the knockout drum of step (f) is integrated into the steam cracking furnace of step (g).

1 . A process for cracking hydrocarbon feedstock containing resid comprising:
 (a) heating a hydrocarbon feedstock containing resid;   (b) adding molecular hydrogen to said heated feedstock to form a mixture stream;   (c) adding a catalyst containing metal-sulfide particles to said heated feedstock and/or said mixture stream;   (d) reacting said mixture in a catalytic hydrovisbreaking reactor under conditions of temperature, pressure and residence time sufficient to catalytically hydrovisbreak at least a portion of said resid into hydrovisbroken hydrocarbon components;   (e) passing said reacted mixture stream into a high pressure separator and separating hydrogen from said reacted mixture;   (f) passing said reacted mixture through a knockout drum to remove catalyst and unreacted or uncracked resid as a bottoms stream; and   (g) passing said catalytically hydrovisbroken hydrocarbon components into a steam cracking furnace and thermally cracking said hydrocarbon components to form light olefins.   
     
     
         2 . The process of  claim 1 , wherein prior to step b) said hydrocarbon feedstock is heated in a convection section of a first steam cracking furnace and mixed with steam, and further comprising separating said heated hydrocarbon feedstock to form an overhead vapor phase and a liquid bottoms phase containing said resid in a first knockout drum integrated with said convection section of said first steam cracking furnace. 
     
     
         3 . The process of  claim 2 , wherein the reacted mixture from step (e) is passed to the convection section of a steam cracker prior to entering the knockout drum of step (f) and wherein the steam cracking furnace of step (g) is a second steam cracking furnace comprising a second integrated knockout drum, wherein said catalytically hydrovisbroken hydrocarbon components are flashed to form an overhead vapor phase and an unconverted liquid bottoms phase. 
     
     
         4 . The process of  claim 3 , further comprising recovering said catalyst by filtering at least a portion of unconverted liquid bottoms from said second integrated knockout drum to form a retentate containing catalyst and a filtrate of unconverted liquid bottoms, and recycling said retentate containing catalyst into said catalytic hydrovisbreaking reactor. 
     
     
         5 . The process of  claim 4 , further comprising blending said filtrate with other refining process streams to produce fuel oil products. 
     
     
         6 . The process of  claim 1 , wherein said catalytic hydrovisbreaking reactor is charged with a catalyst load of between 0.1 wt % and 10 wt %, based on the weight of the hydrocarbon feedstock containing resid introduced into said reactor. 
     
     
         7 . The process of  claim 1 , wherein said catalytic hydrovisbreaking reactor is charged with a catalyst load of between 0.5 wt % and 7.5 wt %, based on the weight of the hydrocarbon feedstock containing resid introduced into said reactor. 
     
     
         8 . The process of  claim 6 , wherein the catalyst load is between 0.5 wt % and 5 wt %, based on the weight of the hydrocarbon feedstock containing resid introduced into said hydrovisbreaking reactor. 
     
     
         9 . The process of  claim 1 , further comprising conducting said catalytic hydrovisbreaking under conditions sufficient to convert greater than 60 wt % of said resid. 
     
     
         10 . The process of  claim 1 , further comprising conducting said catalytic hydrovisbreaking under conditions sufficient to convert between 60 wt % and 80 wt % of said resid. 
     
     
         11 . The process of  claim 1 , where the catalytic hydrovisbreaking conditions include temperatures of 427-482° C., a residence time of 2-100 minutes, a hydrogen treat rate of 89-891 m 3 H 2 /m 3 crude, and an operating pressure of 0.7-21 MPa-gauge. 
     
     
         12 . The process of  claim 1 , where the catalytic hydrovisbreaking conditions include temperatures of 438-460° C., a residence time of 10 to 40 minutes, a hydrogen treat rate of 178-445 m 3 H 2 /m 3 crude, and an operating pressure of 3.45-17.2 MPa-gauge. 
     
     
         13 . The process of  claim 1 , wherein said hydrocarbon feedstock contains between 10 wt % and 50 wt % of resid boiling at 566° C.+. 
     
     
         14 . The process of  claim 1 , wherein the hydrovisbroken hydrocarbon components are passed into the steam cracker without condensation of the hydrovisbroken hydrocarbon components. 
     
     
         15 . The process of  claim 1 , wherein the hydrovisbroken hydrocarbon components comprise 40 wt % to 90 wt % less sulfur than the hydrocarbon feedstock containing resid. 
     
     
         16 . The process of  claim 1 , wherein the molecular hydrogen is added as a gas. 
     
     
         17 . The process of  claim 16 , where in the gas is syngas. 
     
     
         18 . A system for cracking hydrocarbon feedstock containing resid comprising:
 (a) a first steam cracking furnace having a first knockout drum integrated with a convection section of said first furnace;   (b) a catalytic hydrovisbreaking reactor downstream of and in fluid communication with a liquid bottoms extraction portion of said first knockout drum; and   (c) a second steam cracking furnace having a second knockout drum integrated with a convection section of said second furnace, and a radiant cracking section;   
       wherein an inlet of said second steam cracking furnace is downstream of and in fluid communication with said catalytic hydrovisbreaking reactor, and a liquid bottoms extraction portion of said second knockout drum is in fluid communication with said catalytic hydrovisbreaking reactor. 
     
     
         19 . The system of  claim 18 , further comprising a stripping gas line connected to said second knockout drum. 
     
     
         20 . The system of  claim 18 , further comprising a filtration unit disposed between the liquid bottoms extraction portion of said second knockout drum and said catalytic hydrovisbreaker reactor. 
     
     
         21 . A process for cracking hydrocarbon feedstock containing resid comprising:
 (1) heating a hydrocarbon feedstock containing resid in a convection section of a first steam cracking furnace;   (2) passing said heated hydrocarbon feedstock containing resid to a first knockout drum integrated with said convection section of said first steam cracking furnace (optionally mixing with steam) and separating said heated hydrocarbon feedstock to form an overhead vapor phase and a liquid bottoms phase containing said resid;   (3) adding molecular hydrogen to said liquid bottoms phase to form a mixture stream;   (4) adding a catalyst containing metal-sulfide particles to said liquid bottoms phase and/or said mixture stream;   (5) reacting said mixture in a catalytic hydrovisbreaking reactor under conditions of temperature, pressure and residence time sufficient to catalytically hydrovisbreak at least a portion of said resid into hydrovisbroken hydrocarbon components;   (6) passing said reacted mixture stream into a high pressure separator and separating hydrogen from said reacted mixture;   (7) optionally passing said reacted mixture to a convection section of a second steam cracking furnace;   (8) passing said reacted mixture exiting the high pressure separator and/or the convection section of the second steam cracking furnace through a knockout drum integrated into the second steam cracking furnace to form a vapor phase containing catalytically hydrovisbroken hydrocarbon components and to remove catalyst and unreacted or uncracked resid as a bottoms stream; and   (9) passing the vapor phase containing catalytically hydrovisbroken hydrocarbon components into the radiant section of the second steam cracking furnace and thermally cracking said hydrocarbon components to form light olefins.   
     
     
         22 . The process of  claim 21 , further comprising recovering said catalyst by filtering at least a portion of unconverted liquid bottoms from said second integrated knockout drum to form a retentate containing catalyst and a filtrate of unconverted liquid bottoms, and recycling said retentate containing catalyst into said catalytic hydrovisbreaking reactor. 
     
     
         23 . The process of  claim 21 , wherein said catalytic hydrovisbreaking reactor is charged with a catalyst load of between 0.1 wt % and 10 wt %, based on the weight of the hydrocarbon feedstock containing resid introduced into said reactor. 
     
     
         24 . The process of  claim 21 , further comprising conducting said catalytic hydrovisbreaking under conditions sufficient to convert greater than 10 wt % of said resid. 
     
     
         25 . The process of  claim 21 , further comprising conducting said catalytic hydrovisbreaking under conditions sufficient to convert between 60 wt % and 80 wt % of said resid. 
     
     
         26 . The process of  claim 21 , where the catalytic hydrovisbreaking conditions include temperatures of 427-482° C., a residence time of 2-100 minutes, a hydrogen treat rate of 89-891 m 3 H 2 /m 3 crude, and an operating pressure of 0.7-21 MPa-gauge. 
     
     
         27 . The process of  claim 21 , wherein said hydrocarbon feedstock contains between 10 wt % and 50 wt % of resid boiling at 566° C.+. 
     
     
         28 . The process of  claim 21 , wherein said hydrocarbon feedstock is not cooled when passing from the convection section of the first steam cracking furnace to the integrated first knockout drum. 
     
     
         29 . The process of  claim 21 , where in the pressure of the liquid bottoms phase containing said resid produced in step (2) is increased prior to adding hydrogen and/or entering the catalytic hydrovisbreaking reactor. 
     
     
         30 . The process of  claim 21 , wherein the reacted mixture stream exiting the visbreaker is reduced in temperature prior to introduction into the high pressure separator. 
     
     
         31 . A process for cracking hydrocarbon feedstock containing resid comprising:
 (a) heating a hydrocarbon feedstock containing resid;   (b) adding molecular hydrogen to said heated feedstock to form a mixture stream;   (c) adding a catalyst containing metal-sulfide particles to said heated feedstock and/or said mixture stream;   (d) reacting said mixture in a catalytic hydrovisbreaking reactor under conditions of temperature, pressure and residence time sufficient to catalytically hydrovisbreak at least a portion of said resid into hydrovisbroken hydrocarbon components;   (e) passing said reacted mixture stream into a high pressure separator and separating hydrogen from said reacted mixture; and   (f) passing said catalytically hydrovisbroken hydrocarbon components into a steam cracking furnace and thermally cracking said hydrocarbon components to form light olefins.   
     
     
         32 . The process of  claim 31 , wherein prior to step b) said hydrocarbon feedstock is heated in a convection section of a first steam cracking furnace, and further comprising flashing said heated hydrocarbon feedstock to form an overhead vapor phase and a liquid bottoms phase containing said resid in a first knockout drum integrated with said convection section of said first steam cracking furnace. 
     
     
         33 . The process of  claim 31 , wherein the steam cracking furnace of step (g) comprises an integrated knockout drum where said catalytically hydrovisbroken hydrocarbon components are flashed to form an overhead vapor phase and an unconverted liquid bottoms phase. 
     
     
         34 . The process of  claim 32 , wherein the steam cracking furnace of step (g) comprises an integrated knockout drum where said catalytically hydrovisbroken hydrocarbon components are flashed to form an overhead vapor phase and an unconverted liquid bottoms phase. 
     
     
         35 . The process of  claim 1 , wherein the process is continuous.